This pilot interventional in vivo study aims to quantitatively evaluate and compare the amount of adhesive residue left on the skin following removal of extraoral maxillofacial prosthetic adhesives. Five commercially available adhesives will be tested using standardized silicone strips applied to randomized sites on the forearms of healthy volunteers. After 8 hours of wear, the strips will be removed, and adhesive residue will be quantified using gravimetric analysis based on differences in strip weight before and after removal. The study also aims to evaluate adhesive failure modes and compare the cleanability of silicone-based and water-based adhesives. Findings from this study may help clinicians select adhesives that optimize prosthesis retention while minimizing skin irritation and patient burden.

This pilot interventional in vivo study is designed to quantitatively evaluate and compare the amount of adhesive residue left on the skin following removal of extraoral maxillofacial prosthetic adhesives. Adhesive-retained facial prostheses are widely used in maxillofacial rehabilitation; however, residual adhesive remaining on the skin after prosthesis removal may contribute to patient discomfort, skin irritation, and difficulty in daily prosthesis maintenance. Despite its clinical importance, adhesive residue has not been quantitatively evaluated in vivo.

Five commercially available maxillofacial prosthetic adhesives, including silicone-based and water-based formulations, will be evaluated using standardized silicone elastomer strips. Five healthy volunteers between 18 and 30 years of age will be recruited. Thirty test sites will be prepared on the volar surfaces of the forearms, with six sites allocated to each adhesive group through block randomization. Participants with skin diseases, adhesive allergies, systemic conditions affecting skin integrity, pregnancy, lactation, or recent skin injuries will be excluded.

Standardized silicone strips measuring 60 × 20 × 3 mm will be fabricated and coated with a uniform quantity of adhesive. After a drying period of 3 minutes, the strips will be applied to designated skin sites and maintained for 8 hours during normal daily activities. Following removal, the strips will be reweighed using a high-precision analytical balance. Adhesive residue remaining on the skin will be quantified using gravimetric analysis by calculating the percentage difference between initial and final strip weights.

The primary outcome measure is the percentage of adhesive residue remaining on the skin after removal of the prosthetic adhesive. Secondary objectives include assessment of adhesive failure modes and comparison of residue patterns between silicone-based and water-based adhesive systems.

To minimize bias, participant allocation sites will be randomized and both participants and investigators involved in application and evaluation procedures will remain blinded to adhesive identity. Statistical analysis will be performed using one-way analysis of variance followed by post hoc multiple comparison testing. The findings of this study may help clinicians select adhesive systems that optimize prosthesis retention while minimizing skin trauma and patient burden during long-term maxillofacial rehabilitation.

Inclusion Criteria:

• Healthy volunteers aged 18-30 years
• Willingness to participate and provide written informed consent
• No history of skin disease
• No known adhesive allergy

Exclusion Criteria:

• Age below 18 years or above 30 years
• Current use of medications affecting skin integrity or immune function
• Recent skin trauma, surgery, or active skin lesions
• Existing systemic disease affecting skin health
• Pre-existing dermatological conditions
• Pregnancy or lactation
• Known allergy or hypersensitivity to adhesives or silicone materials
• Participation in another clinical trial during the study period

Individual participant data (IPD) will not be shared because the study involves a very small sample size, and de-identification may not fully protect participant confidentiality. Data will be retained by the investigators and may be made available for academic review upon reasonable request, subject to institutional ethics and data protection policies.

Participants and outcome assessors were blinded to adhesive identity. Adhesive allocation was coded during outcome assessment to minimize bias